Ignition system.



L. 'KRIBGBIL IGNITION SYSTEM. APPLICATION FILED MAR. 27, 1914,

Patented Dee. 15, 1914.

VX/illnesses:

U'NiTED vsrA'i-Es PAaENT Enron.

LGIS KRIEGER, OF PARIS, FRANCE, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATIGN 0E NEW YORK.

IGNITON SYSTEM.

To all 'whom t may concern Beit known that I, Louis linmean, a citizen of the French Republic, residing at Paris, France, have invented certain new and useful Improvements in Ignition Systems, of which the following is a specification.

My invention relates to ignition systems for internal combustion engines and is particularly applicable to such systems employing induction coils, the primary of which is supplied with current from a source of substantially constant potential.

My invention has for.its object a novel arrangement and construction of parts whereby the voltage applied to the primary of the induction coil is substantially constant at the time of interruption of the pri mary circuit at all speeds of the engine.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of thisA specification.

For a better understanding of my invention reference may be had to the following description taken in connection with the accompanying drawing, in which Figure l is a set of characteristic curves of the'establishment of current in the pri mary of an induction coil, and Fig. 2 is a diagrammatical View of an ignition system in accordance with my invention.

When an induction coil is employed in an ignition system 'for internal combustion engines and the primary of the inductioncoil is supplied with current'from a direct current source, the impedance of the primary circuit will tend to cause the intensity of the spark to vary with the speed of the engine.

Tnternal combustion engines, as usually constructed, comprise several cylinders and a distributer in the secondary circuit of the induction coil connects the proper cylinders successively to the secondary of the induction coil. The sparks are produced by opening the primary circuit of the induction coil which is immediately closed again, and the current in the primary circuit restablishedv so that the next spark can be reproduced when' necessary. The current inthe primary of the induction coil is not restablished instantaneously, but in accordance with an I Specification of Letters Patent. Patented Dec, 15, 1914 Application filed March 27, 1914.

Serial No. 827,583.

exponential law having for its equation the following:

RT :E 7

of current I on the abscissa OX and the intensity thereof at the time T ou the ordinate OY. Depending upon the speed of the engine, the length of time that the primary circuit is closed may vary from OT to Ot as the speed increases. If a coil is fed with the voltage c, the curve of establishment of current will be Oz'. When the speed is low the primary current has a value AT at the moment of its interruption. The coil then gives good sparks and the ignition is perfect.V lf the speed increases considerably, say to such a value that the duration of contact is only Ot, then the corresponding current is only tb, this small value of current will give only a very feeble spark. The reason for this small value of current is that the flux in the core of the induction coil has not reached its maximum value.

One method of carrying out my invention is to take a source of voltage E capable of furnishing the curve of current establishment OI, but always preserve a duration of the establishment of the current that is constantly equal to Ot, even at low speed. In order to accomplish this, the current would be interrupted during the time OO, the cir cuit being closed only at O, so that OT equals Ot. At this moment the current will be established according to the curve OA, a curve identical with OB, and consequently there would always be a primary current equal to TA at the moment of interruption, at all engine speeds, the time h OO varying, becoming zero at high speeds'. Y ln order to accomplish this the interrupter is constructed so that the angle of rotation i OAz' has the equation I is equal to and is represented by the straight line BA.

. crease of theflux during It will therefore be seen that the curve BDA tends toward the same asymptote as the curve OAz'. As Alis very near A, since it is comprised between A and the asymptote, it ymay be said that practically from t to T the primary current is the same. The spark` then. will always have the same intensity. On the other hand a rapid inthe time' 025 may give without 4any danger a spark; this spark being produced at the beginning of the closure of the Circuit which follows the rupture, will be produced duringthe eXpansion of .the gases and consequently would have no elfect upon the engine.

In Fig. 2 of the drawing, the primary and secondary circuits of the ignition system are inductively related by an induction coil having a primary l anda secondary`2. 3 is a spark plug in the secondary circuit, any number of which may be employed depending upon the number of engine cylinders.` 4 is a suitable source of substantially constant voltage, such as a battery or generator, connected in the primary circuit of the induction coil, as is a resistance 5 and an interrupter 6. The interrupter comprises a contact -member 7 and a plu-l rality of contact segments 8 and 9, the member 7 and the segments being relatively rotatable. Each of the segments is divided into two parts insulated from each other,'

the terminals of the resistance 5 being connected to the parts of each segment. The contact segments 8 and 9 are separated by strips of insulation 12, which 'are wlder than the contact member 7. The contact member 7 is arranged to insert the resistance 5 in the primary circuit of the induction coil for smaller intervals of time as the relative speed of the Contact member and the contact segments increases. I prefer to rotate the contact member 7, as by an arm 10, in which it may be displaced by centrifugal force against a spring 11. The interrupter shown gives two interruptions per revolution, each of them when it clears the strips of insulations 12. The segments 8 and 9 are divided into two parts 8 and 82 and 9 and 92 by thin strips of insulation 13 and when the member 7 engages 8 or 9', the primary of the induction'coil is grounded directly,

lis on 82 or 92',

vtively relating said without the resistance 5 being in circuit. When the member 7 has left 8 or9 and In the primary circuit. The strips of insulation. l2 are preferably arranged so that the contact of member 7 with parts 8" or 9 ofthe segments takes place on arcs increasing with the speed, in order that the duration of this contact be constantly equal tothe time Ot (Fig. 1) and the duration of contact with the parts 82 or 92 will constantly decrease.I By giving the strips of insulation 12 a curved form, upon which the rupture of the primary cir- ,cuit'is made at an angle equal to the necessary variationof lead of the ignition with the speed, the ignition is automatically advanced with the plate carrying the segments 8 and 9 movable, it is possible to make this lead regulable manually.

I desire it to be understood-that my invention is not limited tothe particular arrangement of interrupter shown and described and-that the contactsegments may be developed on a surface of a cylinder instead of on a plane surface as shown, and

such as abc,h

the resistance 5 is connected speed. By making the.

I aim in the appended claims to cover such modifications as not depart from invention.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

l. In an ignition system, primary. and secondary circuits, an induction coil induccircuits, a source of subvoltage in said primary well as any others that do the spirit and scope of my stantially constant circuit, and an interrupter in the primary circuit comprising a contact member and contact segments, said member and segments 1..

being relatively rotatable, said Contact member being capable of being moved under the action of centrifugal force to maintain the voltage applied to that part of the induction coil in the primary circuit substantially constant at the time of interruption at all speeds.

2. In an ignitionv system, primary and secondary circuits, an Ainduction coil inductively relating said circuits, a source of substantially constant voltage in said primary circuit, and an interrupterin the primary clrcuit comprising a contact member andcontact segments, said member and segments being relatively rotatable, said contact memberbeing capable of beingmoved under the' action of'centrifugalforce to maintain the'voltage applied to that part of the induction coil in the primary circuit substantially constant at the time of interruptionat all speeds, said segments being curved at such an anglethat the interruption of said primary circuit varies With the speed and thereby automatically advances the ignition with increase of speed.

3. In an ignition system, primary and secondary circuits` an induction coil inductiyely relating said circuits, a source of substantial y constant yoltage in said primary circuit, a resistance, and an interrupter in said primary circuitcomprising a rotatable contact member and a plurality of contact segments, each of said vsegments being divided into two parts insulated from each other, said resistance being connected to said partsof the segments, said contact member being arranged to insert said resistance in said primary circuit for smaller intervals of time as the speed of saidcontact member increases.

l. In an ignition system,v primary and secondary circuits, an induction coil inductii'ely relating said circuits, a source of substantiallyconstant voltage in said primary circuit, a resistance, and an interrupter in said primary circuit comprising a rotatable contact member and a plurality of contact segments, each of said segments being divided into two parts insulated from each other, said resistance being connected to saidv parts of the segments, said contact member beingI arranged. to insert said resistance in said primary circuit for smaller intervals of time as the speed of said contact member increases, said segments being curved at such an anglethat the interruption 01' the primary circuit Varies With the speed and thereby automatically advances `the ignition with increase of speed.

In an ignition system, primary an secondary circuits, an induction coil inductively relating said circuits, a source of substantially constant voltage in said primary' circuit, a resistance, and an interrupter in said primary circuit comprising a contact member and contact segments, said Contact member and contact segments being relatively rotatable, each of said segments being divided into two parts insulated from each other, said resistance being connected to said parts ot' the segments, said contact member being arranged to insert said resistance in the primary circuit for smaller intervals of time as the relative speed of being arranged to insert said resistance in said primary circuit for smaller intervals of time as the relative speed ot said contact member and contact segments increases,

- said segments being curved at such an angle that the interruption of said primary circuit varies with the speed and thereby automatically advances the ignition with increase ot' speed.:

Iii Witness whereof, I have hereunto set my hand this sixteenth day of March, 1914.

LOUIS KRIEGER.

Witnesses z lLY E. PALMER, WERNER HiLnnBRi-ixo. 

